Steam-generator



(No Model.) 2 Sheets-Sheet 1.

N. W. PRATT. STEAM GENERATOR.

No 428,631. Patented May 27,1890.

WITNESSES.

3. AP 21 I/IVVENTOR. Kw a 7% ATTORNEY.

(No Model.) 2 Sheets- Sheet 2.

-N.- w. PRATT. STEAM GENERATOR.

No. 428,631. Patented May 27, 1890.

WITNESSES. [NVEzVTO/C.

A TTORNEY.

UNITED STATES PATENT OFFICE.

NAT. W. PRATT, OF BROOKLYN, NElV YORK.

STEAM-G EN ERATOR.

SPECIFICATION forming part of Letters Patent No. 428,631, dated May 2'7,1890.

Application filed January 28, 1888' fierial No. 262,210- (No model.)

, To all whom it may concern.-

Be it known that I, NAT. W. PRATT, a citizen of the United States,residing at Brook lyn, county of Kings, State of New York, have inventedcertain new and useful Improvements in Steam-Generators, of which thefollowing is a specification.

This invention relates to sectional watertube steam-boilers wherein theheated furnace gases are passed between ranges of steam-generatingtubesin a direction transverse to the tubes.

In order to enable others to understand and use my said invention, Iwill proceed to describe the details of its construction, andsubsequently point out in the appended claims its novel characteristics.

Referring to the accompanyingdrawings, in which corresponding lettersindicate like parts, Figure 1 is a longitudinal vertical section of aboiler constructed according to my invention, and Fig. 2 a frontelevation partly in section on the line a: 00 of Fig. 1.

A A and A A are groups of generating water-tubes all connectingvertically by serpentine headers or at each end thereof, and by means ofnipples b and c with one another, and by nipples d and ranges of tubes 6with the manifoldsL of the steam-drums D.

O O are the combustion spaces or chambers between the said groups ofgenerating-tubes, the same, as well as the interstices between thetubes, being divided by the central diaphragm B, faced with fire-brickor other suitable material, and extending transversely throughout thebreadth of the boiler-space.

The range of heating-surface maybe extended by the employment ofadditional groups of tubes and combustion-spaces, the invention notbeing limited to the number shown.

The serpentine headers a interlock, as seen in Fig. 2, and form wallswithin which the draft-course is confined, the spaces between thenipples b and series of tubese being closed by fire-brick filling b ande, and in the instance of the opposite ends of the structures the draftbeing confined by the boiler-fronts and doors M. The draft-course istherefore directed upward from the furnace I, through the tubular groupsA A and intervening combustion-space 0, through the combustionspace J,(as in common practice) thence downward through the tubular groups A Aand intervening combustion-space Oto the point of delivery H,- whichlatter in the present instance of a battery of boilers traverses beneaththe entire number, subsequently conducting to the stack or chimney.

The space N, back of each boiler independent of the draft-passages,serves the purpose of access to the hand-holes P opposite the tubes,whereby the products of cleaning are readily removed.

The water-tubes are inclined at substantially a common angle, in themanner usual in boilers of this class, so that upward circulation ispromoted by the heat delivering the current to the front end of thesteam-receiving drum D, thence to the rear and downward through thelower headers a. The mud-drum E, connecting transversely beneath thesaid lower header and having suitable blow-01f appliances, receives suchwater impurities as are separated by gravitation.

K are the steam-pipes connecting the drums D together and with the pointof steam-delivery.

From the hoppers or reservoirs R R beneath the furnace ash-pits theaccummulated ashes are removed by the leveroperating dumping device S,consisting of. a swinging lid pivoted at g and operated by the lever l.

T are receiving-chambers of suitable blowers, (not shown,) from whichair-blast is admitted through dampers 2' to and beneath the grate-bars tto controllably accelerate the draft.

U is a regulating-damper, which maybe automatically or otherwiseregulated to control the draft at its point of exit. The deliveryfiue Oconducting to the main flue H is of a hopper shape, having inclinedsides, and by closing the damper U acts as a receptacle for products ofcleaning from the fines and chambers above, said products being removedthrough the door adjacent to said damper bya suitable implementintroduced from the side.

The boiler-setting herein shown is especially adapted to the location ofbatteries of boilers in the successive stories of a building one aboveanother. The walls "W are sustained upon the I-beams V, carried from thepillars F to and into the walls X, as the side or partition walls of thebuilding. The transverse I-bcams G, extending between the beams V,sustain the furnace front-wall and bridgewall, as shown, the rear of thetubular strncture and the mud-drum being supported by the arch of thesmoke-flue ll. The steamdruin D is suspended beneath each overhangingfloor by rods Y, the weights of the several boiler structures being thussubdivided and distributed.

Having thus fully described my invention, what I claim, and desire tosecure by Letters Patent, is

1. In combination with a water-tube steamboiler having an upward anddownward draft across the tubes, a reservoir, ash-pit, a smokefiue, anda blast-pipe, all arranged substair the hopper when said closing-plateis closed. 30

NAT. W. PRATT. \Vitnesses:

(Jr-ms. L. MOELER, II. E. BUNKER.

